Original comment by @pheyos:

When adding a lot of URLs, the whole Edit Job dialog grows more and more, such that at some point one has to scroll down the complete page to see the controls or the wizard.

Suggestion: Make the list of URLs scrollable when having more than 5 (or so) URLs, so the bottom of the dialog is always visible and has enough space to unfold the wizard without scrolling. Or a better solution might be to move the 'Add custom URL' and edit form to the top of the panel, so that the user doesn't need to scroll down when adding a new URL.